Abstract: 【Objective】 This paper aims mainly to study the growth of body weight and body size of local self-propagating thoroughbred horse foals from 0 to 12 months in the hope of providing data basis for scientific breeding and scientific diet formulation of local self-propagating thoroughbred horse foals by measuring and analyzing the changes of body weight and body size growth. 【Methods】 A total of 40 thoroughbred horse foals with an average body weight of (51.00±6.27) kg (20 males and 20 females) were selected and divided into male foal group and female foal group according to their gender for a 12-month feeding monitoring experiment. All the experimental stables were carried out under the same feeding conditions, the composition and nutritional level of the daily grain were consistent, the weight and body size index of the stables were determined on schedule, and the 0 to 12 month-old pure blood stables and weight data were fitted and analyzed by the Logistic nonlinear growth curve model. 【Results】 (1) With the increase of month age, the weight and body size of the male foal were significantly increased by 6.59% (P<0.01), 2.62% (P<0.01) and 2.28% (P<0.01), and the body height and tube circumference of the male foal were significantly higher than those of the female foal, which increased by 1.05% (P<0.05) and 1.22% (P<0.05) compared with female foal, respectively; (2) There were no significant differences in body weight, body height, chest circumference and average daily growth between male and female foals (P>0.05). The total growth and average daily growth of male foals were significantly higher than those of female foals from 0 to 6 months of age, which were 29.02% (P<0.01) and 27.78% (P<0.01), respectively. The total growth and average daily growth of male foals were higher than those of female foals during the whole experiment period; (3) The fitting degree of body weight and body size growth curve of foals was above 0.93, especially the fitting degree of body weight, body height and chest circumference of foals was 0.973,3, 0.982,4, 0.970,2 and 0.963,3, 0.970,1, 0.981,6, respectively. The fitting degree of growth curve model was good. 【Conclusion】 Under the condition of this experiment, the foal grows with the increase of month age. The weight and body size of the male foal grow faster than those of the female foal, and the increase is more obvious before weaning. The Logistic model can better fit the growth curve of 0-12 month-old pure blood stables weight and body size.